8:02 p.m. ET A third blast in four days rocked the quake-damaged Fukushima Dai-ichi nuclear plant early Tuesday, the country’s nuclear safety agency reported.

The explosion at Dai-ichi Unit 2 — at 6:10 a.m. Tuesday local time — followed two hydrogen explosions as authorities try to avoid a catastrophic release of radiation in the tsunami-devastated area, The Associated Press reported.

Plant owner Tokyo Electric Power Co. said the blast happened near the suppression pool in the reactor’s containment vessel. The pool was later found to have a defect. The company said some employees were temporarily evacuated following Tuesday’s explosion.

5:30 p.m. ET | At this hour, Japanese officials are working to prevent a meltdown at the the Fukushima Dai-ichi plant, restoring water levels used for cooling fuel rods. Officials from the Fukushima prefecture said 190 people had been exposed to radiation, but that the levels in the air had since gone down. Four nuclear facilities were damaged in the earthquake and tsunami, but the Dai-ichi plant has been the most concerning because of its proximity to the Pacific and the damage it sustained in the disaster. Seventeen U.S. military personnel who had participated in rescue efforts were also shown to have been exposed to radiation.

The nuclear concerns have compounded the government’s struggle to house evacuees and help victims who are in need of food and shelter. Many are without power or heat four days after the disaster struck. Bodies have washed ashore, and while the official death toll stands at 1,900, the number is expected to rise sharply as authorities work to identify the dead. An estimated 2,000 bodies came ashore in the Miyagi prefecture.

A series of aftershocks have continued to roil Japan, with a 6.2-magnitude quake on Monday that raised fears of another tsunami.

2:45 p.m. ET | This video from NHK World illustrates the safety measures that failed to operate properly at nuclear reactors in northeastern Japan after Friday’s earthquake and tsunami.

12:15 p.m. ET | Levels of water, used to help cool the core, dropped within one of the plant’s nuclear reactors, exposing uranium fuel rods. Water levels have been increased again, but parts of the rods remain exposed. The concrete encasing appears to be undamaged after an earlier explosion in Unit 3, which officials said relieved some of the pressure. Officials are trying to prevent a full meltdown through that outer containment layer, which would release high levels of radiation.

11:30 a.m. ET| Japan’s Chief Cabinet Secretary Yukio Edano said that it is “highly likely” that fuel rods within three reactors are melting. The outer containment shells are still holding.

11:20 a.m. ET | In remarks at a middle school in Arlington, Va., President Obama began by saying “Like all Americans, I continue to be heartbroken by the images of devastation in Japan and I know all of you, young and old, have been watching the full magnitude of this tragedy.” He expressed support from the American people for “some of our closest friends and allies” and offered continued recovery assistance.

10:30 a.m. ET | Aftershocks are continuing to to rattle Japan after last week’s 8.9-magnitude temblor, adding complications to recovery and rescue efforts.

To see a live view of seismic activity in the region we created a Google Earth map, overlaid with United States Geological Service data. The map will update at least every 30 minutes, showing new aftershocks as red circles. Click below to view it.

Japanese authorities have been scrambling to stave off meltdowns, using seawater to try to cool the reactors. An explosion also occurred on Saturday, and there are fears that if a third unit overheats at the Fukushima plant, there could be another explosion. Tens of thousands have been evacuated from the vicinity of the plant.

55170The Aftermath of the Tsunami in Sendai, JapanAerial footage reveals the wreckage of Sendai, Japan, two days after the town was devastated by a tsunami.2011-03-13 11:45:00disabledYxphzcL_dZI

The Japanese stock market fell 6 percent on Monday, the first full business day since the disaster. Financial analysts around the world are watching to see how the hit to Japan’s economy will affect global markets. Infrastructure damage has already hurt factory production and transportation.

Aerial images have highlighted how significant the destruction was across Japan’s east coast. Friday’s quake was the largest on record in Japan and unleashed a series of powerful aftershocks that continued to rattle the country. The city of Sendai was inundated with water and hundreds died when the torrent swept away cars and homes.

52543Newly released video of the Tsunami and the search for survivors in JapanVideo from Iwate prefecture shows the wave rolling over a seawall, inundating a large city. In another video report, three elderly people are rescued from a car 20 hours after the disaster.2011-03-13 11:54:00disabledCFvy2Lb_wEw

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